Renewable energyRenewable energy is a source of energy that can never be exhausted.
We can obtain renewable energy from the sun (solar energy), from the water (hydropower), from the wind (windmills), from hot dry rocks, magma, hot water springs (geothermal) and even from firewood, animal manure, crop residues and waste (Biomass).

"The future belongs to renewable energy," said Brad Colllins, the executive director of the American Solar Energy Society, a Boulder, Colorado-based nonprofit. Scientists and industry experts may disagree over how long the world's supply of oil and natural gas will last, but it will end, Collins said.

While renewable energy is generally more expensive than conventionally produced supplies, alternative power helps to reduce pollution and to conserve fossil fuels.

"People sometimes get caught up in cost-effectiveness," said Paul Torcellini, a senior engineer at the DOE's National Renewable Energy Laboratory (NREL) in Golden, Colorado. "But it can be a question of values and what we spend our money on."